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Can I powder coat a lathe?

02-20-2015, 08:30 AM

I'm looking at lathes now and I'll likely buy an older used lathe. Something ugly but still somehow beautiful. I love restoration work and the lathe will likely get the full treatment in time. Last year I built a powder coating oven. I prefer it over paint whenever possible. I'm not sure what, if any effect the cure will have on precision equipment. My gut says 400 degrees for 20min will not hurt it but I'd like to know for sure. Will putting the compound tool rest or bed ways in the oven for 20 hurt them? Will it make them brittle or warped? Damage them in any way? Has anyone done this and what were your results?
No powder or paint on working surfaces of course.

Comment

I've done a few cast items with high mass. As long as a preheat the part and preheat the oven to 500 and drop it back down to 400 when I put the part in I've been ok. Just need to get the part up to temp as fast as possible. I'm more worried about effecting the precision.

Comment

I am in agreement with Davek. I restored a doctors bathroom scale, the stand on type with the slide weights and the height measurement gauge. The base and the beam castings are cast iron. Twice I tried powder painting the upper casting (white). First, I cleaned it with Purple Power, figuring it was good to go. Wrong. Apparently the good doctor lubircated the moving parts he could get to and the oil bled through the baked powder, leaving a couple big brown spots in a nice smooth white finish. Back to the blast cabinet. After removing all the baked-on powder, I baked the casting at 500 degrees for at least an hour and re-cleaned again with purple power, then acetone. Second attempt was another failure - more brown spots. The spots were in an area of high visibility. I blasted off the powder a second time and completed the restoration using white Rustoleum aerosol paint. An old lathe would get oiled every time it was used. I know of no professional powder coater that will guarantee the finish on any casting and if they do it twice, they will charge accordingly.

Comment

Pinresto, your enthusiasm make's me smile. I can remember what it was like
getting ready to buy my first lathe. Your mind is going all crazy thinking about
things you want to do to make it look nice, and work good.

Comment

I powder coated my Doall Bandsaw and had oil residue seep through in a few spots where main body was welded to 5/8" thick base plate.He cooked it twice to try to avoid this before coating but still happy how it turned out.You can look at 1950 Doall thread if you would like to ,in the 2nd pic.

Comment

First of all, remember it's a machine tool, not fine furniture or a custom car. A machine shop operates under an entirely different esthetic: the only things that count are good parts within spec, nade of the right material, on time, and within budget. Everyting else is a distant second and that includes paint, texture, Fung Zhue, political correctness, ideological purity, and the power of crystals.

That said, powder coat is a sensible finish for machine tool castings. It's hard, durable, color fast, and resistant to coolants and oil. OTH iron castings are massy and slow to heat. Much longer heat time may be required to flow the powder into a continuous film. Also the casting will have to be clean, free of films and infiltrated liquids. Finshed surfaces may need to be masked and the surfaces to be coated media blasted to give the casting tooth. All this equates to some surgical risk avoided by simple brush painting over a good paint prep.

Slow heating will have little effect on casting stability although there may be metallurgical changes lurking within the metal. It's the rate of heating and the inequality of heat distribution that causes localized expansion and, if excessive, permanent distortion. I suggest you heat the work starting from a cold oven, remove it piece by piece for the powder, then after coating increase the heat on the whole load to cure it. I know little of powder coating but much about protecting precision castings from heat distortion. This is the point where a powder coat process expert should weigh in, review these suggestions and reccommend a suitable process.

Returning to my earlier remarks about esthetics, I suggest you put off fancy paintwork until you get a chance to assess your lathe's condition and invest some TLC, accomplish remedial work, whatever. It's the precision of the machine that counts not its appearance. I suggest you spend your first hundred hours cleaning, repairing what needs to be repaired, acquiring tooling, attachments, and equipment, and accumulating the skills and resources oi takes to put your new machine tool to work.

If your circle of friends downcheck you for owning an ugly machine tool that is otherwise in good condition that performs accurately, efficiently, and predictably, you need another set of friends.

If the bedraggled appearance of your machine really does drive you nuts, strip the machine to basics, clean, prep, and prime, and brush paint a standard color of an alkyd industrial coating. A good two coat paint job on a well prepped surface is almost indistinguishable from a spray-paint job and, because it does not have to be masked and the shop draped to form a paint booth, the job takes half the time.

Another point, paint jobs on machine tools are subject to chip wash and small dings from wrenches and fumbled work, staining. Powder coat and calylized paint is difficult to touch up - it always looks patchy and then here is adhesion. Alkyd paint requires only prep sanding and a dab of paint. Touch it up on Friday close of business and the machine is ready for production on Monday morning.

Comment

I'll raise the question of the effect of 400 degrees on heat treated parts such as hardened ways, and rolling element bearings. I don't know, so I'll look for comments by those more knowledgeable and experienced.

Comment

"Hardener" as in an actual catalyst, or do you mean Japan drier to help it dry faster?

Doc.

Catalyst. When I was going through the 10EE I made the mistake of not using it. Even after a week it was quite tacky. Doing some reading it will take alkyd enamel up to 2 years to fully cure without the catalyst. I ended up having to restrip the lathe and start over. But the stuff holds up real well.

Comment

I'll raise the question of the effect of 400 degrees on heat treated parts such as hardened ways, and rolling element bearings. I don't know, so I'll look for comments by those more knowledgeable and experienced.

This is what I'm concerned about.

Comment

First of all, remember it's a machine tool, not fine furniture or a custom car. A machine shop operates under an entirely different esthetic: the only things that count are good parts within spec, nade of the right material, on time, and within budget. Everyting else is a distant second and that includes paint, texture, Fung Zhue, political correctness, ideological purity, and the power of crystals.

That said, powder coat is a sensible finish for machine tool castings. It's hard, durable, color fast, and resistant to coolants and oil. OTH iron castings are massy and slow to heat. Much longer heat time may be required to flow the powder into a continuous film. Also the casting will have to be clean, free of films and infiltrated liquids. Finshed surfaces may need to be masked and the surfaces to be coated media blasted to give the casting tooth. All this equates to some surgical risk avoided by simple brush painting over a good paint prep.

Slow heating will have little effect on casting stability although there may be metallurgical changes lurking within the metal. It's the rate of heating and the inequality of heat distribution that causes localized expansion and, if excessive, permanent distortion. I suggest you heat the work starting from a cold oven, remove it piece by piece for the powder, then after coating increase the heat on the whole load to cure it. I know little of powder coating but much about protecting precision castings from heat distortion. This is the point where a powder coat process expert should weigh in, review these suggestions and reccommend a suitable process.

Returning to my earlier remarks about esthetics, I suggest you put off fancy paintwork until you get a chance to assess your lathe's condition and invest some TLC, accomplish remedial work, whatever. It's the precision of the machine that counts not its appearance. I suggest you spend your first hundred hours cleaning, repairing what needs to be repaired, acquiring tooling, attachments, and equipment, and accumulating the skills and resources oi takes to put your new machine tool to work.

If your circle of friends downcheck you for owning an ugly machine tool that is otherwise in good condition that performs accurately, efficiently, and predictably, you need another set of friends.

If the bedraggled appearance of your machine really does drive you nuts, strip the machine to basics, clean, prep, and prime, and brush paint a standard color of an alkyd industrial coating. A good two coat paint job on a well prepped surface is almost indistinguishable from a spray-paint job and, because it does not have to be masked and the shop draped to form a paint booth, the job takes half the time.

Another point, paint jobs on machine tools are subject to chip wash and small dings from wrenches and fumbled work, staining. Powder coat and calylized paint is difficult to touch up - it always looks patchy and then here is adhesion. Alkyd paint requires only prep sanding and a dab of paint. Touch it up on Friday close of business and the machine is ready for production on Monday morning.

I understand what your saying but were not all running machine shops. I don't care about time lines and budgets. I'm not going to start stripping it for powder coating the second I get it. I was just wondering if it was an option. As far a someone looking down on me for having an ugly lathe......lol.